Drill grinding apparatus



S. NIQUET DRILL GRINDING APPARATUS Aug. 20, 1963 Filed Jan. 21, 1963 ywvszvran Samuel N/OUE T tates 3,10d,956 DRILL GRINDING APPARATUS SamuelNiquet, 172 Bates St, New Bedford, Mass.

Filed Jan. 21, 1963, Ser. No. 252,750 6 Claims. (Cl. 511-219 The presentinvention relates to a drill grinding apparatus and more particularly tosuch an apparatus capable .of grinding the cutting lips at the point ofthe drill.

The general object of the present invention resides in the provision ofan apparatus of the character described which is capable of grindingseveral drills simultaneously.

Another important object of the present invention reatet sides in theprovision of an apparatus of the character the provision of a machine orapparatus of the character 7 described in which drills with left hand orright hand twisted flutes may be ground.

The foregoing and other objects of the present invention will becomemore apparent during the following disclosure and by referring to thedrawings in which:

FIGURE 1 is perspective view of the apparatus in accordance with theinvention; j

FIGURE 2 is a top plan view of part of the same;

FIGURE 3 is a partial elevation of a drill; and

FIGURE 4 is an end elevation of the point thereof.

Referring now more particularly to the drawings in which likereferences, characters indicate like elements throughout the apparatusin accordance with the invention is adapted to grind or sharpen thepoint of conventional twist drills provided with spirally arrangedflutes 2 each defining a cutting edge 3 having a land or narrow strip 4immediately trailing the same. i

The drill point has a generally conical point, the cutting lips 5 beingat an angle a with the drill axis, this cutting angle of the drill beingusually about 59 and the heel surface 6 trailing each cutting lip 5sloping away from the cutting lips 5 at a lip clearance angle ofapproximately 12 to 15.

The intersection of the heel surfaces 6 results in the formation of acentral chisel point or dead center 7 which extends across between thecutting lips 5.

The apparatus comprises a U-shaped support rod 8 the transverse leg 9 ofwhich is freely pivoted within two spaced journal members 10 which aresecured to a base plate 1.1. The free legs 12. of rod 8 extend at rightangles to transverse leg 9 and are parallel to each other and disposedin the same plane and their free ends are provided with rest blocks 13preferably of cylindrical shape. The blocks 13 are secured to legs 12 atthe same level.

An arm 14 is secured to the central portion of transverse leg 9 and isprovided at its rear outer end with an adjustment screw 15 which abutsagainst base plate 11.

Bracing strips 16 are secured to the rear end of arm 14 at 17 and theirother ends are each provided with a hole through which passes a free leg12 of support rod 8, said other ends being located just underneath theassociated rest block 13. i

The resulting supporting assembly is disposed in a ice 2 suitablerelationship with a bevelled grinding wheel 13 which is driven by asuitable electric motor 19'. The bevelled surface 20 of grinding wheel18 is oriented in such a way, with its drive shaft 21 being horizontalthat the vertical plane tangent to said bevelled surface 20 will beparallel to the line joining the corners defined by the top surfaces ofthe rest blocks 13 with the forward surfaces of the portion of the freelegs 12 protruding upwardly from rest blocks 13. These corners act asabut ment and journal surfaces for the legs 22' of L-shaped pivot rods23, the other legs 24 of which are secured to and rigidly interconnectedat their free ends by a transverse bar 25. Legs 24 are parallel to eachother and in the same plane while pivot legs 22 are co-ax-ial and spacedfrom each other. The legs 24 are slidable through bores made at the endsof a second bar 26 and their position may be adjustably locked withinbar 26 by means of set screw 27. The center of second bar 26 is providedwith a notch 28, the bottom of which is at an angle with respect to theright angular faces of bar 26 which has a rectangular cross section.Notch 28 receives the underface portion andside face portions of aslotted main bar 29 which is rigidly secured to second bar 26 by meansof a bolt 31? passing through the slot 31 of main bar 29 and screwedwithin a threaded bore of second bar 26.

An abutment and guiding plate 32 is secured to the upper end of slottedmain bar 29, said plate is disposed in a plane at right angles to thelong axis of main bar 23 and across the end thereof, being provided witha right angular flange 33 extending underneath and secured to the upperend portion of bar 29. The top abutment edge 34 of plate 32 is recessedwith respect to end lugs 35.

A rectangular suppont plate 36 is positioned over main bar 29 andextends across the same. Plate 36 is secured to an underlying guidingblock 37 which slidably fits within slot 31 of bar 29 such that theentire plate 36 can be slid along bar 29' while remaining parallel toitself. Guiding block 37 protrudes from the lower edge of plate 36 and aclamping strap 38 is secured thereto by means of a rivet or the like.

Clamping strap 38 overlies the top face and side faces of the main bar29 and is provided with a set screw 40 which engages the correspondingside face of the main bar 29 to firmly lock the rectangular plate 36 inadjusted position longitudinally of the main bar 29.

A channel member 41 is secured by rivets 42 or the like to the top faceof plate 36 and is disposed longi tudinally thereof- A block 43 isarranged for, guided movement over plate 36 in accordance with thedouble arrow 44. Block 43 has a notch 45 made at the underface thereofin which fits the protruding portion of the channel member 41. A setscrew 46 is threaded through block 43 with the free end of the shank ofsaid screw protruding through notch 45 to engage underneath lip 47 ofchannel member 41; when the set screw 46 is loose, the block 43 may beslide along lip 47 while being retained thereto by the protruding end,of the set screw; when the latter is screwed tight against the web ofthe channel member 41, the block 43 is locked in adjusted position onplate 36. p

A strip 48 rests on the top face. of the Web of the channel member 41and passes through the notch 45 of block 43 and is provided at one endwith an upstanding flange 49. When set screw 46 is tightened, strip 48is locked in position with respect to block 43 and also with respect tomain plate 36; when set screw 46 is loose, strip 48 may be adjustedtransversally with respect to the plate 36 as well as block 43 so as toadjust the distance between flange 49 and one or the other of thebevelled end faces 50 of block 43. The position of strip 48 may bereversed from that shown in FIGURE 1 with the a 22 of the pivot rods 23,angular position of the cutting-lip with respect to the long axis ofeach drill is automatically obtained due flange 49 disposedon the righthand side instead of the left hand side of block 43.

The apparatus in accordance with the invention is used as follows:

A plurality ofdrills 1 to be sharpened are disposed on the abutment andguiding plate 32 between its end lugs 35 and on the rectangularplate 36with their shank end abutting against channel member 41 with the outerdrills of the setabutting against flange 49 of strip 48 and one or theother of bevelled end faces 50' of block 43. In this position, thedrills lie in a plane substantially. parallel to main bar 29' and abovethe latter. One

or more drills up to 12. or:15 may be positioned inthismanner. Thelongitudinal position of strip- 48 is adjusted to maintain the drillsinside by side contiguous relationship after the transverse position ofblock 43 had been adjusted laterally of plate 36 in order to adjust theinclination of the several drills in accordance with the cutting angleoz of the tips of said drills. If desired, the lip 47 of channel member41 may be graduated in degrees to facilitate lateral adjustment of block43 in accordance with the cutting angle of the drills.

The drills may be-inclined towards the right or left with respect to themain bar 29 in accordance whether they have lefthand-or right hand twistflutes, by positioning said drills on one side or the other of block 43and. by reversing the position of strip 48 accordingly. The longitudinalposition. of the rectangular platev 36 with respect to main bar 29 isalso adjusted in accord- 1 ance with the length of the particular set ofdrills being sharpened or to be sharpened. The plate 36 is adjusted suchthat the tip end of the drills will protrude approximately Ms of an inchfrom the transverse alined .legs in this manner, the correct to the factthat the outtingedges 3 of the two diametrically opposed flutes 2 reston the edge 34 of guiding plate 32. i

The bevel of the notch 28 made in bar 26 is such that the L-shaped rods23 are disposed in a plane makes approximately-a 22 angle with the planeofslotted bar 29.

Y Bar 26 is longitudinally adjusted in a permanent manher by means ofbolt 30 along main bar 29 in such position that the axes of legs 22 ofrods 23 will be connected by a line passing through the abutment edge 34of plate 32] The degreeof clearance desired for the heel surfaces 6,that is the lip clearance angle, is obtained by adjusting 24 inaccordance with the lip clearance angle. obtainable.

and also for various diameters of drills.

Once the drill holding apparatus has been adjusted as above described,the position of the rest blocks 13 and therefore of the pivot legs 22 ofrods 23 towards or away from the surface 20 of the grinding wheel isadjusted by screwing or unscrewing the adjustment screw 15 to therebypivot leg'9 Within journal members with this adjustment the tips of thedrills 1 are brought into grinding contact with the abrading surface 20of the grinding wheel 18.

Once the apparatus has been adjusted, the drills are pressed in positionagainst the edge 34 of plate 32 and against rectangular plate 36 withone hand while the other hand grasps the outer end of main bar 29 andmoves the entire assembly in .a swinging vertical movement about the pivotsconstituted by legs 22 of rods 23. The entire arouses assembly isalso simultaneously transversally displaced by sliding legs 22 on therest blocks 13 so as to vary the lateral zone of engagement of the drilltips with the grinding surface of wheel 18.

Once one lip 5 of the drills has been sharpened together with theassociated heel surface 6 the drills of the entire set are turnedthrough half a turn so as to be able to sharpen the other lip andassociated heel surface.

From the foregoing, it is apparent that several drills may be sharpenedsimultaneously and that the apparatus is highly flexible because it cansharpen drills of different diameters and lengths and also withdifferent cutting angles and lip clearance angles.

It will also be noted that the grinding streaks or ridges formed ontheheel surface 6 extend back away from the cutting lip 5 rather thantransversely thereacross. Thus, the heel surface has a minimum bindingfriction with a Work piece and the drill operates more smoothly.

Drills sharpened with the. apparatus of the invention. have been foundto last much longer before a subsequent resharpening is required.

While a preferred embodiment in accordance with the invention has beenillustrated and described, it is understood that various modificationsmay be resorted to without'departing from the spirit and scope of theappended claims.

What I claim is:

1. Multiple drill grinding apparatus comprising rotatable abrasiveinea-ns having agrinding surface presenting a substantially flattransverse operative portion, and drill holding means associated withsaid abrasive means, said holding means comprising spaced support andpivot means disposed at the level of said operative portion of saidgrinding surface and on each side thereof, the line connecting saidspaced support and pivot means being substantially parallel to saidoperative portion, a U-shaped support frame including a transversemember, spaced parallel legs and spaced axially aligned pivot membersdepending from said legs at an angle thereto, said pivot membersengaging said support and pivot means for swinging movement with respectto said support and pivot means, a bar carried by said frame anddisposed between said legs and longitudinal ly thereof, multiple drillsupport means carried by said bar to hold a plurality of drills side byside and in contiguous relationship with the longitudinal axes of saiddrills inclined to said operative portion of said grinding surface at anangle equal to the cuttug angle of the drill tips and with the tips ofsaid drills in the vicinity of a l ne joining the axes of'saicl pivotmembers and offset from said line, whereby, with a cutting lip andassociated heel surface of said several drills held in contact with saidoperative portion of said grinding surface, swinging movement of saidframe about said support and pivot means will produce sharpening of saidcutting lip and grinding of said heel surface of each of said severaldrills.

2 Multiple drill grinding apparatus as claimed in claim 1 wherein saidpivot members are also supported on said support and pivot means fortransverse displacement of said frame with respect to, said support andpivot means so as to laterally displace the portion of said drill tipsin engagement with said operative portion of said grinding surfacelaterally of the latter.

3. Multiple grinding apparatus as claimed in claim 1, wherein said drillsupport means support said drills in a plane substantially parallel tothat of said frame and said frame is mounted at an angle to the plane ofsaid legs,

and further including means to vary the position of said pivot membersWith respect. to the adjacent end of said frame longitudinally of saiddrill tips from the line joining the axes of said pivot members.

4. Multiple drill grinding apparatus as claimed in claim 1, wherein saidmultiple drill support means include a support member secured to the endof said frame adjacent said pivot members and defining a drill engagingsupport edge, lugs upstanding from said edge at both ends thereof,

and a support plate mounted on said frame in an area spaced from saidsupport edge and having means forengaging the shank ends of said drills,said support plwe adjustable longitudinally on said frame to therebyadjust the length of the tip portion of said drills protruding from saidsupport edge, said last named means adjustably movable transversely ofsaid frame to thereby vary the inclination of said drills with respectto the long axis of said frame.

5. Multiple drill grinding apparatus as claimed in claim 4, wherein saidframe is mounted at an angle with respect to the plane passing throughsaid legs, and said drill support edge is disposed on a lineintercepting the long axes of said legs, and means to vary the positionof said pivot members with respect to said support edge longitudinallyof said frame to thereby vary the degree of offset of the drill tipsWith respect to a line joining the axes of said pivot members.

6. A multiple drill grinding apparatus as claimed in claim 1, furtherincluding means to adjust the position of said support and pivot meanstowards and away from said operative portion of said grinding surface.

References Cited in the file of this patent UNITED STATES PATENTS3,089,290 Wurm-Reithmayer May 14, 1963

1. MULTIPLE DRILL GRINDING APPARATUS COMPRISING ROTATABLE ABRASIVE MEANSHAVING A GRINDING SURFACE PRESENTING A SUBSTANTIALLY FLAT TRANSVERSEOPERATIVE PORTION, AND DRILL HOLDING MEANS ASSOCIATED WITH SAID ABRASIVEMEANS, SAID HOLDING MEANS COMPRISING SPACED SUPPORT AND PIVOT MEANSDISPOSED AT THE LEVEL OF SAID OPERATIVE PORTION OF SAID GRINDING SURFACEAND ON EACH SIDE THEREOF, THE LINE CONNECTING SAID SPACED SUPPORT ANDPIVOT MEANS BEING SUBSTANTIALLY PARALLEL TO SAID OPERATIVE PORTION, AU-SHAPED SUPPORT FRAME INCLUDING A TRANSVERSE MEMBER, SPACED PARALLELLEGS AND SPACED AXIALLY ALIGNED PIVOT MEMBERS DEPENDING FROM SAID LEGSAT AN ANGLE THERETO, SAID PIVOT MEMBERS ENGAGING SAID SUPPORT AND PIVOTMEANS FOR SWINGING MOVEMENT WITH RESPECT TO SAID SUPPORT AND PIVOTMEANS, A BAR CARRIED BY SAID FRAME AND DISPOSED BETWEEN SAID LEGS ANDLONGITUDINALLY THEREOF, MULTIPLE DRILL SUPPORT MEANS CARRIED BY SAID BARTO HOLD A PLURALITY OF DRILLS SIDE BY SIDE AND IN CONTIGUOUSRELATIONSHIP WITH THE LONGITUDINAL AXES OF SAID DRILLS INCLINED TO SAIDOPERATIVE PORTION OF SAID GRINDING SURFACE AT AN ANGLE EQUAL TO THECUTTING ANGLE OF THE DRILL TIPS AND WITH THE TIPS OF SAID DRILLS IN THEVICINITY OF A LINE JOINING THE AXES OF SAID PIVOT MEMBERS AND OFFSETFROM SAID LINE, WHEREBY, WITH A CUTTING LIP AND ASSOCIATED HEEL SURFACEOF SAID SEVERAL DRILLS HELD IN CONTACT WITH SAID OPERATIVE PORTION OFSAID GRINDING SURFACE, SWINGING MOVEMENT OF SAID FRAME ABOUT SAIDSUPPORT AND PIVOT MEANS WILL PRODUCE SHARPENING OF SAID CUTTING LIP ANDGRINDING OF SAID HEEL SURFACE OF EACH OF SAID SEVERAL DRILLS.